In a Zinc Bromine (ZnBr) hybrid flow battery, two aqueous electrolyte solutions contain the reactive components, which are based on zinc and bromine elements, stored in two external tanks. During the charging/discharging phases, these two electrolyte solutions flow through the cell stack consisting of carbon-plastic composite electrodes with compartments. Thus, the reversible electrochemical reactions occur in these electrolytic cells (Luo et al., 2015).
Flow batteries can be used for multiple applications, however due to their typical size and economics, they are best suited for small to medium scale temporal storage applications (IRENA, 2017). This factsheet focuses on long-term electricity storage for applications such as load shifting, typically with discharge times of >1 hour.